Anti-cancer compound and pharmaceutical composition containing the same

ABSTRACT

The invention relates to a compound of formula (I), more specifically in the levorotatory form (1 a ) thereof, in particular the form having a rotatory power [α]D=−38.6+0.7 at a concentration of 0.698 mg/ml in methanol. The compound may be in the form of a base or an acid addition salt, in particular a pharmaceutically acceptable acid. The compound is a selective Aurora A and B kinase inhibitor and can be used as an anticancer drug.

The present invention relates to the compound of formula (I):

and to the pharmaceutical composition comprising it. This compound ispreferably the levogyratory compound (Ia). This compound can be used asan anti-cancer ingredient. The invention also relates to a process forpreparing the compound (I) or (Ia) and also to some of the intermediatesin said process.

TECHNICAL PROBLEM

A number of cancer treatment strategies are aimed at inhibiting theAurora-type kinases, particularly Aurora A and B, which are involved inthe regulation of mitosis; in this regard, see Nature Reviews 2004, 4,927-936; Cancer Res. 2002, 94, 1320; Oncogene 2002, 21, 6175; Mol. Cell.Biol. 2009, 29(4), 1059-1071; Expert Opin. Ther. Patents 2005, 15(9),1169-1182; Clin. Cancer Res. 2008, 14(6), 1639.

Some Aurora inhibitor compounds (for example, MLN-8237 from Millennium,AZD-1152 from Astra-Zeneca or SNS-314 from Sunesis) are presently underevaluation in clinical trials. MLN-8237 is selective for Aurora A whileAZD-1152 is selective for Aurora B. Since both kinases, Aurora A and B,are deregulated in cancer, inhibiting both Aurora A and B provides anadvantage relative to selective inhibition of one kinase or the other.Moreover, multikinase compounds are in existence, such as the compoundAT-9283 from Astex, which inhibit a number of kinases, including AuroraA and B. For this type of compound it is difficult to predict that theinhibition of the Aurora kinases might actually be exploited clinically,since the inhibition of kinases other than Aurora A and B is likely togive rise to side effects. One technical problem the invention intendsto solve is therefore that of developing a compound which is a potentand selective inhibitor of Aurora A and B.

The cyclic nucleotide phosphodiesterase enzyme PDE3 plays a major partin the signalling mediated by the cyclic nucleotides cAMP and cGMP thattakes place in the myocytes of the smooth cardiac and vascular muscles.The inhibition of PDE3 by small molecules has an inotropic andvasodilatory action, which may prove to be useful on a short-term basisfor the treatment of certain cardiomyopathies in which defects incardiac contraction are a feature. It has been shown, however, that thelong-term use of these molecules increases mortality among this type ofpatient. Furthermore, the use of PDE3 inhibitors in patients who do notpresent this type of pathology, such as patients affected by cancer, maygive rise to unwanted effects on cardiac rhythm. It is thereforeimportant, in the context of an anti-cancer therapy, not to inhibitPDE3. In this regard, see Exp. Opin. Invest. drugs 2002, 11, 1529-1536“Inhibitors of PDE3 as adjunct therapy for dilated cardiomyopathy”; Eur.Heart J. supplements 2002, 4(supplement D), D43-D49 “What is wrong withpositive inotropic drugs? Lessons from basic science and clinicaltrials”. Another technical problem the invention intends to solve isthat the Aurora A and B inhibitor compound shall not inhibit the enzymePDE3.

It is also important that the anti-cancer ingredient presents ametabolic stability (see section 10.2.2 of “Chimie pharmaceutique” G. L.Patrick, De Boeck, published 2003, ISBN=2-7445-0154-9). The reason isthat the inadequacy of the pharmacokinetics of pharmaceutical compoundsis one of the primary reasons for failure in their development (Curr.Pharm. 2005, 11, 3545 “Whydrugs fail—a study on side effects in newchemical entities”). Moreover, the metabolism is often a majordeterminant of clearance, of drug interactions, of intra-individualvariability in pharmacokinetics, and of clinical efficacy and toxicity(Curr. Drug Metab. 2004, 5(5), 443-462 “Human hepatocytes in primaryculture: the choice to investigate drug metabolism in man”). Anothertechnical problem the invention intends to solve is that the Aurora Aand B inhibitor compound shall exhibit high chemical and metabolicstability.

PRIOR ART

Bioorg. Med. Chem. Lett. 2002, 12, 1481-1484 describes in table II thecompound 6A, which has a different tricyclic structure.

WO 01/36422 describes compounds having a different tricyclic structure.

WO 2004/005323 describes the compound E5A29 of formula (a):

as an EPO receptor having a different tricyclic structure. Furthermore,the compound does not include a phenyl ring substituted by the group—O-benzimidazolyl at the top of the tricyclic ring system.

WO 2005/016245 describes anti-cancer compounds having a differenttricyclic structure, of formula (by

in which R₄ may represent a substituted phenyl group. Substitution bythe —O-benzimidazolyl group is neither described nor suggested.

WO 2007/012972 and EP 1746097 describe anti-cancer compounds of formula(C)

and, in one embodiment, of the formula (c′):

R₂ represents a substituted aryl or heteroaryl group. X represents N orCR₇, R₅ and R₆ may both represent H or CH₃. No example in WO 2007/012972contains the group

which characterizes the compound of formula (I). Moreover, among thecompounds resolved. WO 2007/012972 teaches that it is dextrogyratorycompounds which are the most active on Aurora A or B (cf. ex. 119 and120 in the table on page 147).

WO 02/062795 describes compounds of formula (d):

in which R₄ and R₅ may optionally form a 5- or 6-membered ring.

BRIEF DESCRIPTION OF THE INVENTION

The invention relates to the compound of formula (I):

more particularly in its levogyratory form (Ia), particularly thatexhibiting the optical rotation [α]_(D)=−38.6±0.7 at a concentration of0.698 mg/ml in methanol. The compound may exist in the form of a base oran addition salt with an acid, particularly a pharmaceuticallyacceptable acid. This compound is a selective inhibitor of Aurora A andB kinases. It can be used as an anti-cancer ingredient.

The invention also relates to a pharmaceutical composition comprisingthe compound and at least one pharmaceutically acceptable excipient, andto the medicament comprising the compound.

The invention also relates to the process for preparing the compound,comprising;

-   -   reacting together the three compounds below. PG denoting a        protective group for the NH function of the benzimidazole

to give the compound:

-   -   deprotecting the NH function of benzimidazole, to give the        compound of formula (I);    -   where appropriate, isolating the levogyratory compound.

The reaction between the three compounds is carried out in an alcohol atreflux, particularly 1-butanol. The following intermediates also formpart of the invention:

PG may be, for example, the group

DESCRIPTION OF THE INVENTION

The invention relates to the compound of formula (I):

This compound may exist in a racemic form or in the form of the twolevogyratory (Ia) and dextrogyratory (Ib) enantiomers. The levogyratorycompound (Ia) has a selective inhibitory activity on Aurora A and Bkinases which is much greater than that of the dextrogyratory enantiomer(Ib). The levogyratory compound (Ia) also has an anti-proliferativeactivity which is greater than that of the dextrogyratory enantiomer(Ib) (see Table 1).

The three compounds (I), (Ia) and (Ib) may exist in the form of a baseor an addition salt of an acid, The salt is advantageously prepared witha pharmaceutically acceptable acid (see P. Stahl, C. Wermuth; Handbookof Pharmaceutical Salts; Wiley Ed. ISBN-13: 978-3906390260, ISBN-10:3906390268), although the salt of any other type of acid, which may beused, for example, for a purification or isolation step, also forms partof the invention.

The compounds (I) and (Ia) may be used as anti-cancer ingredients or forpreparing a medicament for treating a cancer. The cancer is moreparticularly a cancer in which Aurora A and/or B kinase(s) are/isinvolved.

The compounds (I), (Ia) and (Ib) are obtained according to Scheme Ibelow:

step 1: the NH function of a 2-halo-benzimidazole (Hal=Br or Cl) isprotected using a protective group PG, to give A1. PG-X represents areagent which introduces the protective group PG. PG may be, moreparticularly, dihydropyran

and, in that case. PG-X represents 3,4-dihydro-2H-pyran

step 2: A1 is reacted with 3-formyl-phenol in the presence of a baseproducing the corresponding phenolate ion, to give B1. The base may bean alkali metal hydride, such as NaH, for example. The reaction iscarried out in a polar aprotic solvent such as DMF;step 3: B1, 3-amino-2-ethoxycarbonylpyrrole and 1,3-cyclohexanedione arereacted with one another, for example in an alcohol (e.g. 1-butanol) atreflux, to give C1;step 4: the NH function of C1 is deprotected, to give the compound (I).The deprotection conditions are dependent on the nature of PG. Forexample, where PG represents dihydropyran, a strong acid is used;step 5: using, for example, a chiral chromatography, the two enantiomers(Ia) and (Ib) are isolated.

For each of steps 1-5, reference may be made to the specific conditionsdescribed in example 1.

EXAMPLES Analytical Methods Method LC/MS-A

The products for analysis are separated on an Acquity Beh C18 HPLCcolumn, 1.7 μm 2.1×50 mm (Waters) thermostated at 70° C. and eluted at aflow rate of 1 ml/min with a gradient from acetonitrile containing 0.1%formic acid (solvent B) into water containing 0.1% formic acid (solventA); elution programmeme: isocratic stage at 5% of solvent B for 0.15min, gradient from 5% to 100% of solvent B in 3.15 min then return tothe initial conditions over 0.1 min. The products are detected by anAcquity PDA diode-array UV/vis detector (Waters, wavelength rangescanned: 192-400 nm), a Sedex 85 light scattering detector (Sedere,nebulizing gas: nitrogen, nebulizing temperature: 32° C., nebulizingpressure 3.8 bar) and an Acquity SQD mass spectrometer (Waters,operating in positive and negative mode, mass range scanned: 80 to 800amu).

Method LC/MS-B

The spectra were obtained on a Waters HPLC-SQD instrument in positiveand/or negative electrospray ionization mode (ES+/−), under thefollowing liquid chromatography conditions:

column: ACQUITY BEH C18 1.7 μm, 2.1×50 mm; T_(column): 50° C.; flowrate: 1 ml/min;solvents: A: H₂O (01% formic acid); B: CH₃CN (0.1% formic acid);gradient (2 min): 5% to 50% B in 0.8 min; 1.2 min: 100% B; 1.85 min 100%B; 1.95 min 5% B.

¹H NMR

The spectra are recorded on a Bruker spectrometer, the product beingdissolved in DMSO-d6. The chemical shifts δ are expressed in ppm.

IR

The infrared spectrum is recorded on a Nicolet Nexus spectrometer, on aKBr disc, with a resolution of 2 cm⁻¹.

Measurement of the Optical Rotation

The optical rotations were recorded on a Perkin-Elmer 341 polarimeter.

Elemental Analysis

The elemental analyses were made on a Thermo EA1108 analyser.

Measurement of the Activity on Aurora A and B

The capacity to inhibit the kinase activity of the enzyme is estimatedby measuring the residual kinase activity of the enzyme in the presenceof different concentrations of the test compound (generally from 0.17 to10 000 nM). A dose-response curve is produced, which allows an IC₅₀ (50%inhibitory concentration) to be determined. The kinase activity ismeasured by a radioactive assay of the amount of radioactive phosphate(³³P) incorporated into a fragment of the protein NuMA (Nuclear MitoticApparatus protein) after 30 minutes of incubation at 37° C. The testcompound is first dissolved at different concentrations in dimethylsulphoxide (DMS (J). Reaction takes place in the wells of a FlashPlatemicrotiter plate (Nickel Chelate FlashPlate-96, PerkinElmer). Each well(100 μl) contains 10 nM Aurora A, 500 nM NuMA, 1 μM ATP and 0.2 μCiATP-γ-33P in a buffer of 50 mM Tris-HCl, pH=7.5; 10 mM MgCl₂; 50 mMNaCl, 1 mM dithiothreitol. The final percentage of DMSO is 3%. Afterhomogenization by stirring, the plate is incubated at 37° C. for 30minutes. The contents of the wells are then removed and the wells arewashed with PBS buffer. The radioactivity is than measured using aTRILUX 1450 Microbeta counter (WALLAC). In each plate, there are eightcontrol wells: four positive controls (maximum kinase activity), forwhich measurement is made in the presence of enzyme and substrate and inthe absence of compound of the invention, and four negative controls(background) for which measurement is made in the absence of enzyme,substrate and test compound. The measurements are given in Table I.

Aurora A

The recombinant human enzyme Aurora A used is expressed in entire formwith a poly-Histidine tag in N-terminal position and is produced in E.coli. A fragment (amino acids 1701-2115) of the human protein NuMA, witha poly-Histidine tag in C-terminal position, is expressed in recombinantform in E. coli.

Aurora B/Incenp

The entire human enzyme Aurora B is coexpressed with a fragment of thehuman protein Incenp (aa 821-918) in a baculovirus system and isexpressed in insect cells. Aurora B has a poly-Histidine tag inN-terminal position, while the Incenp fragment possesses aGlutathione-S-Transferase (GST) tag in N-terminal position. The twoproteins form a complex which is called Aurora B/Incenp. A fragment(aa1701-2115) of the human protein NuMA with a poly-Histidine tag inC-terminal position is expressed in recombinant form in E. coli. Thisfragment is used as substrate.

Measurement of the Cell Proliferation

Cells (tumour cell line HeLa—ref.: ATCC CCL-2 and HCT116 ref.: ATCCCCL-247) are contacted with the test compound for 96 hours, with¹⁴C-thymidine added during the last 24 hours. The cell proliferation isestimated by the amount of ¹⁴C-thymidine incorporated in the cells.

The test compound is dissolved to form a stock solution at 10 mM inDMSO, and this stock solution is used to produce a range of serialdilutions, generally from 10 000 μM to 0.3 μM, these serial dilutionsbeing themselves diluted 1/50 in the cell culture medium (20× solution)which will be used for 1/20 dilution in the cell culture plates. Thefinal concentrations of the test compound will generally be between 10000 and 0.3 nM.

D0: the cells are seeded in 96-well Cytostar plates in 180 μL of culturemedium. The plates are then placed in an incubator at 37° C., 5% CO₂ forfour hours. The test products are then added in a volume of 10 μL perwell, starting from a 20× solution. This solution contains 2% of DMSO inthe culture medium. The final concentration of DMSO is therefore 0.1%.The plates are then placed in an incubator at 37° C./5% CO₂ for 72hours.D3: after 72 hours, 10 μL per well of ¹⁴C-thymidine at 10 μCi/mL in theculture medium are added. The plates are then placed in an incubator at37° C., 5% CO₂ for 24 hours.D4: The incorporation of ¹⁴C thymidine is measured on a Micro-Betaradioactivity counter (Perkin-Elmer) after this 24-hour, “pulse” period.The total time of treatment of the cells with the test product is 96hours.

The percentage inhibitions IC50 are calculated in Excel using thefollowing formula:

${I\mspace{14mu} \% \mspace{14mu} {Inhibition}} = {100*\left( {1 - \left( \frac{X - {Blank}}{{CC} - {Blank}} \right)} \right)}$

X=Measurement for the Sample CC=Cell Control

Blank=Measurement in the wells without cells

IC₅₀ is calculated using the XLfit software (IDBS. UK) with the aid offormula 205, with the parameter D (Hill number) locked to a value of 1.The results are given in Table I.

Evaluation of the Effect of the Compounds of the Invention on theActivity of the Enzyme PDE3

The effect of the compounds of the invention on the activity of theenzyme PDE3 was evaluated by the company CEREP (Le bois I'Evêque, 86600Celle I'Evescault, France; http://www.cerep.fr) in accordance with itsstandard protocol (see Bender, A. T., Beavo, J. A. Pharmacol Rev. 2006,58, 488-520: the enzyme PDE3A in recombinant form is expressed in Sf9cells, the substrate is cAMP and the residual AMPc is measured by HTRF.The reference inhibitor in the test is milrinone, whose IC₅₀ is 270 nM.The residual activity % are related to the control without inhibitor).The results are expressed either as the concentration which inducesinhibition by 50% (IC₅₀) or as a percentage inhibition measured at a setconcentration of the compound. The results are given in Table I.

Measurement of the Chemical Stability of the Compounds

The chemical stability of the compounds was measured in various media:0.05 N hydrochloric acid in a 50/50 (v/v) water/acetonitrile mixture;0.05 N sodium hydroxide in a 50/50 (v/v) water/acetonitrile mixture;sodium phosphate buffer, 25 mM, pH=7.4, in a 50/50 (v/v)water/acetonitrile mixture; sodium phosphate buffer 25 mM, pH=7.4, in a50/50 (v/v) water/acetonitrile mixture containing 1% (w/v) ofbenzylamine hydrochloride; sodium phosphate buffer, 25 mM, pH=7.4 in a50/50 (v/v) water/acetonitrile mixture containing 1% (v/v) of2-mercaptoethanol. The compounds are diluted in the media under study ata final concentration of 100 μM, by dilution of a 10 mM stock solutionin DMSO. The solutions are stored at 20° C. for a total time of 48hours, and the concentration of the compounds under study is measuredover time (t=0, 1, 6, 12, 24 and 48 hours) by HPLC. HPLC analysis iscarried out with an Agilent system 1100 instrument equipped with a diodearray detector on a Luna 018 column, 30×4.6 mm, 3 μm (Phenomenex) whichis eluted with a gradient from acetonitrile (solvent B) into watercontaining 0.5% (v/v) of formic acid (solvent A) at a flow rate of 1.5ml/min and a temperature of 25° C. The elution programme consists of agradient from 10 to 90% solvent B in 5 minutes, followed by an isocraticstage of one minute at 90% of solvent B, and return to the initialconditions over one minute. The concentration of the products understudy is estimated from the height and area of the characteristic peakof the product under study on a chromatogram at the maximum wavelengthof each product. The area and the height measured at each time ofsampling are related to the area and height obtained for the sample attime 0. When degradation is observed, a half-life is measured from theresulting time-concentration curve. The results are given in Table II.

Evaluation of the Metabolism in the Presence of Microsomal Preparationsof Human and Murine Livers.

Whereas microsome preparations remain important in determining themetabolic stability of a pharmaceutical compound, primary hepatocyteculture allows a more detailed evaluation of its intrinsic clearance,and better vitro-vivo correlations suggest hepatic clearance in humans.

The compounds of the invention (5 μM) are incubated at physiologicaltemperature over human and murine microsomal liver fractions (1 mg/ml ofproteins), diluted in a phosphate buffer, in the presence of bovineserum albumin (1 mg/ml BSA), and the reduced form of nicotinamideadenine dinucleotide phosphate (1 mM NADPH). To terminate incubation,four volumes of acetonitrile containing corticosterone as internalstandard (IS) are added. The samples are centrifuged and thesupernatants are analysed by liquid chromatography/tandem massspectrometry coupling (LC/MS-MS). The LC/MS-MS analysis is performed ona QTRAP API4000 mass spectrometer (Sciex) equipped with an 1100 serieschromatography system (Agilent) and a Pal CTC automatic injector, Thedata are acquired and analysed using Analyst 1.4.1 software. The samplesare separated on a 3 μm C18 Polaris column, eluted at a flow rate of 0.7ml/min with a gradient from acetonitrile (solvent B) into watercontaining 0.1% formic acid (solvent A). The elution programme iscomposed of the gradient from 20 to 90% of solvent B in 2 minutes, anisocratic stage at 90% of solvent B, for 0.9 minute, and a return to theinitial conditions in 0.1 minute. The area of the chromatographic peaksfor the compound and for the internal standard are integrated using theAnalyst-Classic algorithm. The metabolic stability of the products ofthe invention is estimated by comparing the integration ratios (ioncurrents of the compounds/ion current IS) measured after 0 minute (t0)and 20 minutes (t20) of incubation. The metabolic stability is thenexpressed as a percentage disappearance in accordance with the followingformula:

Metabolism %=(ratio of peaks at t0−ratio of peaks at t20)/ratio of peaksat t0

The results are given in Table III.

Evaluation of the Clearance in the Presence of Human Hepatocytes.

The compounds of the invention (0.5 or 5 μM) are incubated for 24 hoursin 48-well plates covered with collagen in the presence of fresh orcryopreserved human hepatocytes (˜200 000 cells/well) obtained fromspecific donors, in an incubator at a physiological temperature. Theincubations are carried out with a culture medium (HAM F12-William E).At various times (0; 0.5; 1; 2; 4; 6; 8 and 24 hours), 100 μl aresampled from each well, and the kinetics are halted by addition of 700μl of a 70/30 (v/v) acetonitrile/water mixture containing corticosteroneas internal standard (IS). The cells are then dissociated and theintracellular and extracellular media are mixed and stored in frozenform at −20° C. prior to their analysis. Following thawing, the samplesare centrifuged at 300 g for 20 minutes and the supernatants areanalysed by liquid chromatography/tandem mass spectrometry coupling(LC/MS-MS). The LC/MS-MS analysis is performed on a QTRAP API4000 massspectrometer (Sciex) equipped with an 1100 series chromatography system(Agilent) and a Pal CTC automatic injector. The data are acquired andanalysed using Analyst 1.4.1 software. The samples are separated on a 3μm C18 Polaris column, eluted at a flow rate of 0.7 ml/min with agradient from acetonitrile (solvent B) into water containing 0.1% formicacid (solvent A). The elution programme is composed of the gradient from20 to 90% of solvent B in 2 minutes, an isocratic stage at 90% ofsolvent B, for 0.9 minute, and a return to the initial conditions in 0.1minute. The concentration of the products of the invention is measuredby integrating the ion current of the characteristic ions of theproducts, relative to the internal standard (IS). The compound/IS ratiosobtained are related to calibration standards of known concentrations,thereby allowing the concentration of the products of the invention tobe ascertained. The intrinsic clearance (expressed in ml.h⁻¹.10⁻⁶ cells)is then determined from the kinetic profiles (concentration/time), usingthe WinNonLin software (5.0). The results are given in Table IV.

Example 1 Preparation of ethyl8-oxo-9-[3-(1H-benzimidazol-2-yloxy)phenyl]-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]auinoline-3-carboxylate(I)

A1. 2-Chloro-1-(tetrahydro-pyran-2-yl)-1H-benzimidazole (CAS No.208398-29-2)

A 10 l reactor is charged, under argon and with stirring, with 2.5 l ofTHF, 180 g of 2-chlorobenzimidazole (1.18 mol) and 325 ml of3,4-dihydro-2H-pyran (6.56 mol, 3 eq.). The reactor is heated untildissolution occurs (temperature of the mixture: 40° C.). Then 6.3 g ofpara-toluenesulphonic acid (0.033 mol, 0.028 eq.) are introduced. Thetemperature is held at between 49 and 52° C. for 2.5 h. Cooling takesplace at 12° C. and 7.65 g of sodium methoxide (0.142 mol, 0.12 eq.) areadded, with stirring maintained for a total time of 15 min. Thetemperature is then taken to 18° C., 5 l of n-heptane are added, and thewhole mixture is filtered on 300 g of Clarcel FLO-M, the retentate beingwashed with 5 l of n-heptane. The filtrate is concentrated to drynessunder reduced pressure to give 292.6 g of2-chloro-1-(tetrahydro-pyran-2-yl)-1H-benzimidazole in the form of aslightly yellow oil (quantitative yield). ¹H NMR (400 MHz, DMSO-d6):1.42 to 2.01 (m, 5H); 2.21 to 2.34 (m, 1H); 3.69 to 3.78 (m, 1H); 4.12(d, J=11.4 Hz, 1H); 5.72 (dd, J=2.4 and 11.2 Hz, 1H); 7.22 to 7.34 (m,2H); 7.82 (d. J=72 Hz, 1H); 7.78 (d, J=7.2 Hz, 1H).

B1: 3-[1-(Tetrahydro-pyran-2-yl)-1H-benzimidazol-2-yloxy]benzaldehyde

Two 2 l three-necked round-bottomed flasks, each equipped with acondenser, a thermometer and a stirrer shaft, are charged under argonwith N,N-dimethylformamide (0.4 l per flask), and 3-hydroxybenzaldehyde(68.5 g, flask 1; 64.2 g, flask 2; 1.08 mol). Sodium hydride (60%dispersion in mineral oil) is then added in portions (flask 1: 26 g;flask 2; 24 g; 1.25 mol, 1.2 eq.), the maximum temperature during theaddition being 32° C.2-chloro-1-(tetrahydro-pyran-2-yl)-1H-benzimidazole (A1), purityestimated at 85%) is then introduced (flask 1: 151 g in 0.5 l ofN,N-dimethylformamide; flask 2: 142 g in 0.5 l of N,N-dimethylformamide;1.05 mol, 0.97 eq.). The mixture is than heated at reflux (temperature140° C., temperature rise time 40 min) and the reflux is maintained for1 h. Heating is then stopped and the mixture is allowed to cool over 1.5h. The contents of the two flasks are combined. The combined mixture ismixed slowly into 5 l of ice-water. The aqueous phase obtained is thenextracted with 4×2.5 l of ethyl acetate (AcOEt). The organic phases arethen combined, washed with 3 l of water and then with 2 l of saturatedNaCl solution, and finally dried by addition of MgSO₄ overnight. Theorganic phase obtained is then filtered on a glass frit (porosity 4) andconcentrated to dryness under reduced pressure to give 385 g of a brownoil (LC/MS-A, tr (retention time)=1.86 min, MS positive mode:m/z=323.16).

A fraction of 158 g of the crude product obtained above is dissolved hotin 1.5 l of an n-heptane/AcOEt mixture (8/2 by volume), combined with500 g of silica (70-30 mesh), and the mixture is stirred for 45 min. Theresulting suspension is filtered on Celite, and washed with 3 l of ann-heptane/AcOEt mixture (8/2 by volume). The organic phase obtained isconcentrated to dryness under reduced pressure. The residue isresuspended in 200 ml of isopropyl ether by mechanical stirring andultrasound treatment, and then filtered on a glass frit (porosity 3).The resulting solid is washed with 2×40 ml of isopropyl ether and driedunder reduced pressure at 40° C. for 16 h to give 68 g of solid. Asimilar treatment applied to the remainder of the crude product produces87.8 g of solid. The solids obtained are combined and homogenized togive 155.8 g of3-[1-(tetrahydro-pyran-2-yl)-1H-benzimidazol-2-yloxy]benzaldehyde in theform of pale beige crystals (LC/MS-A, tr=1.87 min, MS positive modem/z=323.13). MS (LC/MS-B): tr=1.00 min; [M+H]⁺: m/z 323; ¹H NMR (400MHz, DMSO-d6): 1.54 to 1.82 (m, 1H); 1.63 to 1.84 (m, 2H); 1.92 to 2.03(m, 2H); 2.30 to 2.42 (m, 1H); 3.70 to 3.79 (m, 1H); 410 (d, J=11.5 Hz,1H); 5.74 (dd, J=2.1 and 11.1 Hz, 1H); 7.13 to 7.22 (m, 2H); 7.43 (d,J=7.3 Hz, 1H); 7.65 (d, J=7.3 Hz, 1H); 7.73 (t, J=7.8 Hz, 1H); 7.78 to7.83 (m, 1H); 7.87 (d, J=7.8 Hz, 1H); 7.96 (s, 1H); 10.05 (s, 1H).

Washing of the silica phases used above with 2 l of an n-heptane/AcOEtmixture (1/1 by volume) produces 67 g of product following concentrationto dryness under reduced pressure. This product is taken up in 2 l of ann-heptane/AcOEt mixture (9/1 by volume), combined with 285 g of silica(70-30 mesh), stirred and treated with ultrasound for 1 h. Thesuspension is then filtered on Celite and the solid phase is washed with2 l of an n -heptane/AcOEt mixture (9/1 by volume). The filtrate isconcentrated to dryness under reduced pressure and the residue istriturated in 400 ml of an n-heptane/ethanol mixture (95/5 by volume),filtered on a glass frit (porosity 3) and dried under reduced pressureto give 35 g of3-[1-(tetrahydro-pyran-2-yl)-1H-benzimidazol-2-yloxy]benzaldehyde in theform of pale beige crystals (LC/MS-A, tr=1.93 min, MS positive modem/z=323.16).

C1: Ethyl8-oxo-9-{3-[1-(tetrahydro-pyran-2-yl)-1H-benzimidazol-2-yloxy]phenyl}-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylate

A 2 l conical flask is charged, with magnetic stirring, with 50 g of3-amino-2-ethoxycarbonylpyrrole hydrochloride and 0.204 l of 2N sodiumhydroxide solution. The mixture is stirred for 15 minutes at ambienttemperature (AT), and then extracted with 3×0.3 l of dichloromethane.The organic phases are combined, dried over MgSO₄ and concentrated todryness under reduced pressure. The residue is triturated withn-pentane, filtered and dried under reduced pressure to a constantweight, to give 36.4 g of 3-amino-2-ethoxycarbonylpyrrole in the form ofa brown solid.

A 2 l three-necked round-bottomed flask equipped with a stirrer shaft, athermometer and a condenser is charged with 1.2 l of 1-butanol, 145 g of3-[1-(tetrahydro-pyran-2-yl)-1H-benzimidazol-2-yloxy]benzaldehyde (0.405mol, B1), 62.4 g of 3-amino-2-ethoxycarbonylpyrrole (1 eq., 0.405 mol),46.8 g of 1,3-cyclohexanedione in 97% form (1 eq., 0.405 mol) and 70.5ml of N,N-diisopropylethylamine (1 eq.) and the mixture is taken toreflux (temperature rise time 55 min, reflux maintained for 30 min,temperature 114° C.) The mixture is then cooled to AT and concentratedto dryness under reduced pressure to give 290 g of a brown oilcontaining ethyl8-oxo-9-{3-[1-(tetrahydro-pyran-2-yl)-1H-benzimidazol-2-yloxy]phenyl}-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylate(LC/MS-A, tr=1.96 min. MS positive mode m/z=553.33). A similar operationcarried out with 35 g of3-[1-(tetrahydro-pyran-2-yl)-1H-benzimidazol-2-yloxy]-benzaldehyde(0.098 mol, example B1) produces 72 g of a brown oil containing ethyl8-oxo-9-{3-[1-(tetrahydro-pyran-2-yl)-1H-benzimidazol-2-yloxy]phenyl}-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylate(LC/MS-A, tr=1.96 min. MS positive mode m/z=553.35).

D1: Ethyl8-oxo-9-[3-(1H-benzimidazol-2-yloxy)phenyl]-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylate(compound I)

A 2 l round-bottomed flask is charged with 224 g of the brown oilcontaining ethyl8-oxo-9-{3-[1-(tetrahydro-pyran-2-yl)-1H-benzimidazol-2-yloxy]phenyl}-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylate(example 1.3), 0.7 l of ethanol and 0.243 l of 2N hydrochloric acid. Themixture is stirred at AT for 16 h and then filtered on a glass frit(porosity 4). The filtrate is concentrated to dryness under reducedpressure and the residue is triturated with 0.5 l of isopropyl ether.The solid obtained is dried under reduced pressure at a constant weightto give 253 g of a brown solid containing ethyl8-oxo-9-[3-(1H-benzimidazol-2-yloxy)phenyl]-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylate(LC/MS-A, tr=1.46 min. MS positive mode m/z=469.29). A similar operationcarried out with 54 g of the brown oil containing ethyl8-oxo-9-{3-[1-(tetrahydro-pyran-2-yl)-1H-benzimidazol-2-yloxy]phenyl}-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylate(C1) produces 60 g of a brown solid containing ethyl8-oxo-9-[3-(1H-benzimidazol-2-yloxy)phenyl]-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylate(LC/MS-A, tr=1.48 min. MS positive mode m/z=469.29).

An aliquot fraction of 0.8 g of the product obtained may be purified bychromatography on a 50 g silica cartridge (10-90 μm) (Biotage SNAP,KP-Sil) eluted with an isocratic stage of dichloromethane of 20 min,then a gradient from 0 to 1% by volume of isopropanol in dichloromethaneover 1 h, and, finally, an isocratic stage ofdichloromethane/isopropanol (99/1 by volume) of 20 min. The fractionscontaining the expected product are combined to give 0.21 g of a yellowsolid. The products of two similar chromatographic separations carriedout on the same scale are crystallized from acetonitrile to give a totalof 0.16 g of ethyl8-oxo-9-[3-(1H-benzimidazol-2-yloxy)phenyl]-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylatein the form of beige crystals (LC/MS-A, tr=1.61 min. MS positive modem/z=469.28). ¹H NMR (400 MHz, DMSO-d6): 1.29 (t, J=7.0 Hz, 3H); 1.80 to1.97 (m, 2H); 2.19 to 2.27 (m, 2H); 2.55 to 2.69 (m, 1H); 2.81 (dt,J=4.8 and 17.2 Hz, 1H); 4.26 (q, J=7.0 Hz, 2H); 5.11 (s, 1H); 6.73 (d,J=3.3 Hz, 1H); 7.02 to 7.16 (m, 5H); 7.25 (t, J=7.9 Hz, 1H); 7.31 to7.38 (m, 2H); 8.34 (s, 1H); 11.33 (broad s, 1H); 12.26 (broad s, 1H).Elemental analysis: C=68.72%; H=5.10%; N=11.82%; H₂O=0.38%.

Example 2 Leyopyraton/enantiomer (Ia) of ethyl8-oxo-9-[3-(1H-benzimidazol-2-yloxy)phenyl]-4,5,6,7,8,9-hexahydro-2H-pyrrole[3,4-b]quinoline-3-carboxylate

The levogyratory enantiomer is purified from the crude product ofexample D1 on a Welk-01RR chiral column, 10 μM, 80×350 mm (Regis. USA)eluted with an n-heptane/dichloromethane/ethanol/triethylamine mixture(50/47.5/2.5/0.1 by volume). The elution of the products is detected byUV spectroscopy at 265 nm. Amounts of 10 g of the crude productdescribed in example D1 are injected in each operation. Under theseconditions, the peak corresponding to the levogyratory enantiomer iseluted with a tr of between 50 and 80 min. The fractions of purifiedlevogyratory enantiomer corresponding to the operations needed to purify310 g of the crude product described in example D1, are combined,homogenized and concentrated to dryness under reduced pressure to give50 g of a beige solid. Mass spectrum (LC/MS-B): tr=0.77 min; [M+H]+: m/z469; [M−H]−: m/z 467. ¹H NMR (400 MHz, DMSO-d6): 1.29 (t, J=7.1 Hz, 3H);1.79 to 1.97 (m, 2H); 2.19 to 2.27 (m, 2H); 2.55 to 2.66 (m, 1H); 2.81(dt, J=4.9 and 17.1 Hz, 1H); 4.26 (q, J=7.1 Hz, 2H); 5.12 (s, 1H); 6.73(d, J=3.4 Hz, 1H); 7.02 to 7.16 (m, 5H); 7.25 (t, J=8.3 Hz, 1H); 7.29 to7.41 (m, 2H); 8.32 (s, 1H); 11.31 (broad s, 1H); 12.26 (broad s, 1H).IR: principal bands: 1678; 1578; 1525; 1442; 1188; 1043 and 743 cm⁻¹.Optical rotation: [α]_(D)=−38.6±0.7 at c=0.698 mg/ml in methanol.Elemental analysis: C=68.18%; H=5.92%; N=11.22%; H₂O=1.25%.

Example 3 Dextrogyratory enantiomer (Ib) of ethyl8-oxo-9-[3-(1H-benzimidazol-2-yloxy)phenyl]-4,5,6,7,8,9-hexahydro-2H-pyrrolo[3,4-b]quinoline-3-carboxylate

The dextrogyratory enantiomer is obtained by purification of thepurified product from example D1 by chromatography on a Welk-01SS chiralcolumn, 10 μM, 60×350 mm (Regis, USA) eluted with an n-heptane/ethanolmixture (7/3 then 6/4 by volume). The elution of the products isdetected by UV spectroscopy. The fractions of the dextrogyratoryenantiomer are combined, homogenized and concentrated to dryness underreduced pressure to give 1.9 g of a yellow powder. MS (LC/MS-B): tr=0.77min; [M+H]+: m/z=469.2; [M−H]−: m/z=467.2. Optical rotation:[α]_(D)=+53.1±1.1 at c=3.6 mg/ml in methanol.

Examples 4-13

the compounds of examples 4-11 were prepared according to the teachingof WO 2007/012972 (see process of claim 26). The tricyclicdihydropyridine products of formula (II) may be prepared according toScheme II:

A mixture of one equivalent of pyrazole (X═N) or ofpyrrole-2-carboxylate (X═COOEt), one equivalent of aldehyde R—CHO andone equivalent of diketone derivative (Y═CH₂, CMe₂, N-Boc) is heated atreflux in an alcohol such as ethanol or 1-butanol for a period ofbetween ½ h and several h, The mixture is then cooled to ambienttemperature. The desired products are isolated by filtration or else thesolvent is evaporated to dryness. If necessary, the crude product ispurified by chromatography on silica gel or else by high-performancepreparative liquid chromatography (HPLC).

When Y represents N-Boc, the products may be deprotected using asolution of trifluoroacetic acid in dichloromethane (50/50) or else asolution of hydrochloric acid in dioxane (Scheme III):

The aldehydes of general formula (III), that are used in the preparationof the compound 4 (R═H), may be obtained according to Scheme IV. Rdenotes one (n=1) or more substituents (n from 2 to 4) on thebenzimidazole nucleus, which are selected from the following: H, F, Cl,Br, OH, SH, CF₃, OCF₃, OCH₃, SCF₃, SCH₃, OCHF₂, OCH₂F, SCH₂F,(C₁-C₆)alkyl, O-allyl, phenyl optionally substituted by one or morehalogen atoms.

step 1; the aldehyde function of 3-iodo-benzaldehyde is protected usingan alcohol protective group and more particularly a diol protectivegroup (ethylene glycol for example) in the presence of an acid such aspara-toluenesulphonic acid in an inert solvent such as toluene and at atemperature of between 20° C. and the boiling temperature of thereaction mixture;

step 2: the intermediate formed is reacted with a product of formula(IV) in the presence of a palladium complex such asbis(dibenzylideneacetone)palladium, a phosphine derivative such asbis[(2-diphenylphosphino)phenyl]ether and a base such as sodiumtert-butoxide, in an inert solvent such as toluene and at a temperatureof between 20° C. and the boiling temperature of the reaction mixture;

step 3: the aldehyde function is deprotected in the presence of anaqueous acid solution such as hydrochloric acid, optionally in a solventsuch as acetone and at a temperature of between 20° C. and the boilingtemperature of the reaction mixture.

Table I compares the Aurora A and B inhibition activities, theanti-proliferative activities on the lines HeLa and HCT116, the PDE3inhibition activity and the metabolism. It is found that compound (I) or(Ia) exhibits a high level of inhibition of Aurora A and B kinases andalso very good activity on the lines HeLa and HCT116.

TABLE I IC50 Aurora IC50 IC50 IC50 IC50 Human Mouse B/Incenp Aurora AHeLa HCT116 PDE3 microsome microsome Example Compound [nM] [nM] [nM][nM] [nM] [%] [%] 1-inventive (I) 4 6 205 nd 78% inhibition at 1000 nM37% 31%

2-Inventive Levogyratory compound (Ia) 1 1 67 20 4000 32% 50% 3-Dextrogyratory compound 900 3800 >10000 nd nd nd nd comparative (b) 4-comparative

6 72 9 664 nd nd 77% 67% 5- comparative

6 23 9 663 nd nd nd nd 6- comparative

13 109 >10000 nd nd nd nd 7- comparative

4 3 430 nd nd 65% 96% 8- comparative

21 102 6 863 nd nd 80% 84% 9- comparative

8 15 9 462 nd nd nd nd 10- comparative

9 22 6 692 nd nd nd nd 11- comparative

107 1755 >10000 nd nd nd nd 12- comparative

3 4 16 1 68 75% 81% 13- comparative

10 11 20 nd 93% inhibition at 1000 nM 53% 74% nd: not determined

TABLE II HCl 0.05N NaOH Phosphate buffer 25 mM Phosphate buffer 25 mMPhosphate buffer 50/50 water/ 0.05N 50/50 pH = 7.4 50/50 pH = 7.4 + 1%benzylamine 25 mM pH = 7.4 + 1% 2- Compound acetonitrilewater/acetonitrile water/acetonitrile 50/50 water/acetonitrilemercaptoethanol 50/50 water/acetonitrile Compound 12 stable stablestable stable unstable (half life t_(1/2) = 2.06 h) (comparative)Compound 2 stable stable stable stable stable (levogyratory compound(Ia))

TABLE III Metabolism measured in the presence Metabolism of humanmicrosomal measured in the presence Example fraction of murinemicrosomal fraction Compound 12 75% 81% (comparative) Compound 2 32% 50%(levogyratory compound (Ia))

TABLE IV Intrinsic clearance measured in the presence of human Examplehepatocytes (in ml · h⁻¹ · 10⁻⁶ cells) Compound 12 0.29 (average of 3determinations obtained with 3 (comparative) different preparations ofhepatocytes) Compound 2 0.121 (average of 5 determinations obtained with5 (levogyratory different preparations of hepatocytes) compound (Ia))

1. A compound of formula (I):


2. The compound according to claim 1 in levogyratory form.
 3. Thecompound according to claim 2, exhibiting an optical rotation[α]_(D)=−38.6±0.7 at a concentration of 0.698 mg/ml in methanol.
 4. Thecompound according to claim 1, in the form of a base or addition saltwith an acid.
 5. A selective inhibitor of Aurora A and B kinasescomprising the compound of claim
 1. 6. An anti-cancer agent comprisingthe compound of claim
 1. 7. (canceled)
 8. A pharmaceutical compositioncomprising the compound according to claim 1 and at least onepharmaceutically acceptable excipient.
 9. (canceled)
 10. A process forpreparing the compound according to claim 1, comprising: reactingtogether the three components below, PG denoting a protective group forthe NH function of the benzimidazole

to give the compound: deprotecting the NH function of the benzimidazole,to give the compound of formula (I); where appropriate, isolating thelevogyratory compound.
 11. The process according to claim 10, whereinthe reaction between the three compounds is carried out in an alcohol atreflux.
 12. The process according to claim 10 wherein PG represents thegroup


13. A compound selected from the following list:

where PG denotes a protective group for the NH function of thebenzimidazole.
 14. The compound according to claim 14, wherein PGrepresents the group


15. (canceled)
 16. A method of treating a cancer in a patient in needthereof comprising administering to said patient a therapeuticallyeffective amount of the pharmaceutical composition of claim
 8. 17. Theprocess according to claim 11, wherein the alcohol is 1-butanol.